If you have tried saving a Visio 2010 drawing as a web page and then displaying it in a Page Viewer web part in SharePoint then you will know that by default hyperlinks in the drawing will no longer work.

This is because the default output format for Visio 2010 drawings being saved as a web page is XAML. When you save the drawing as a web page a collection of files are generated one of which is called xaml_1.js. Opening the Visio drawing .htm file directly in the browser works as expected and hyperlinks are active. However, if you try to display the Visio drawing inside a Page Viewer web part you will see a JavaScript error that references the xaml_1.js file seemingly because there is conflict with DOM elements that exist in the standard SharePoint page.

I suspect that this didn't receive much attention during testing by Microsoft as the assumption could be that if you are using Visio 2010 you will also be using SharePoint 2010 and Visio Services to display your Visio drawings in the browser.

There is a way to work around this by changing the output format of Visio to VML (Vector Markup Language) instead of XAML. Unless you choose VML the first time you save as a web page then Visio remebers the XAML default and there is no setting in Visio (that I can find!) that allows you to change this default. The only option left is to crack open the registry and go searching for the relevant setting.